That was Pete Carroll's persona during his five years with the Jets, four as defensive coordinator and one as head coach. While most NFL taskmasters roam the hallways of their buildings with a scowl, with agita, with a dyspeptic grimace, Carroll strolled Weeb Ewbank Hall on Hofstra's campus with . . . a harmonica.

It became, unintentionally, a symbol of his philosophy.

"The harmonica was always in his hand," former Jets defensive lineman Jeff Lageman recalled for Newsday this past week.

Carroll and defensive line coach Greg Robinson drove to the team's facility together in those days, and it wasn't a short trip. Carroll was never good at doing nothing.

"Pete, not wanting to waste down time, actually taught himself how to play the harmonica going back and forth to work," Lageman said. "He loves music, so he taught himself how to play the harmonica. He was finding a way to utilize that time in a positive way. That's Pete. Positive, positive, positive."

It's easy for Carroll to be that way now. He's built the Seahawks into a contender in his own image, a team that loves to compete and have fun. They'll play Sunday against the 49ers for a chance to advance to Super Bowl XLVIII.

But even in the infancy of his head-coaching days, when it was hard to find optimism with the Jets or when he was sandwiched between the dictatorial coaching regimes of Bill Parcells and Bill Belichick in New England, his former players recall an energy that was infectious and ever-present.

Like string theory, Carroll was constantly vibrating and creating life.

"He was the most energetic coach I had in my 11-year career," former Jets cornerback Victor Green said.

NFL Network analyst Willie McGinest, who played for Carroll with the Patriots, said, "Once you talk to Pete, once you're around him, you feel the energy, the enthusiasm, his knowledge of the game."

Added Lageman: "When Pete walked into a room, the energy went up . . . I can tell you in my 10-year career, I never had more fun than I did playing for Pete."

He may come across as quirky, eccentric and unorthodox -- he's one of the few NFL head coaches who has an active Twitter feed -- but it gets a response from players. Mostly good. But not always.

A basket case

One of the ways that personality manifested itself was in what Jets players found when they took the field for the start of 1994 training camp, their only one under Carroll. As they went outside the weight room, they found that their first-year head coach, then only 42, had installed a pickup basketball court.

Some who had played under Carroll on the Jets' defense knew his affinity for hoops. He often would participate in offseason games with players at Hofstra's gym. But to put a court in the middle of training camp?

"That was a changeup," Green said with a chuckle. "I don't know if there is any head coach who will have a basketball goal set up at training camp. We're a football team, not a basketball team."

"It's the little things," former Jets wide receiver Rob Carpenter said of Carroll's tactics. "Old-school coaches might call it unorthodox, but he just does that to take the edge off guys every now and then."

It was, the players remembered, all about competition. That's what Carroll wanted to instill in everything he did. Even the harmonica- playing. It was, Lageman reflected, a challenge within.

"Instead of the Western way, it's more of an Eastern philosophy," Lageman said, comparing Carroll's Zen to Phil Jackson's. "You compete within. Competition is not always external . . . Western philosophy is: What's the end result? Did you kill the dragon? Eastern philosophy is: It's not about the end result, it's about the journey and getting to that point. It's just different."

Not everyone was on board with that with the Jets or the Patriots.

"If you were a high-paid guy, you expected to play," Carpenter said of the Jets' culture under Bruce Coslet, who was fired 20 years ago this month and replaced by Carroll. "But that's not Pete's thing. I'm sure it did rub a few guys the wrong way."

"We had a lot of veterans," Green said of the 1994 squad, which included eight players with at least 10 years of NFL experience, among them Boomer Esiason, Art Monk and Ronnie Lott. "I think we had too many veterans for a young guy like Pete."

Esiason was one of the few veterans who was enamored of Carroll. "He was a great coach to play for," the CBS analyst said. "I never really had a coach who prepared me the way he did."

Carroll's time with the Jets was undone by another veteran quarterback. Dan Marino. The Jets were playing the Dolphins in a late-season game and a win would have tied them for first in the AFC East. But Marino's fake spike -- a play in which he pretended to clock the ball but threw a touchdown pass instead -- gave Miami the win and the Jets didn't win another game that season. They finished 6-10.

"Given what happened toward the end of that season with the spike game and everything, I never got a chance to experience [Carroll as a head coach] past that year," Esiason said, "which was unfortunate for me."

Carroll ran into similar resistance in New England, where he made the playoffs in the first two of his three seasons and never finished below .500, but could not push the team deep into the postseason.

"I just don't think we had enough guys buying into it," McGinest said. "If they did, I think we would have been a much better football team."

Tedy Bruschi, now an ESPN analyst, was one of those young Patriots players who did buy in. The narrative is often presented that Bill Belichick arrived in New England in 2000 and turned the franchise around, winning the Super Bowl after the 2001 season.

"I really think that Pete had a direct result on the success we had after he left," Bruschi said. "We had key players develop under his tutelage in those three years, three hidden years that people forget about . . . If Pete had one more year, he would have turned it around."

They love footballAfter he was fired from his second head-coaching job in six seasons -- he was a defensive coordinator for the 49ers for two seasons between his tenures with the Jets and Patriots -- Carroll took his enthusiasm and bubbly outlook to the place where it would be most likely to succeed: college.

He was hired by Southern California and quickly found that his philosophies resonated much better with younger players. He won the AP national championships in the 2003 and 2004 seasons, won the BCS championship in the 2004 season, and lost in the BCS final in the 2005 season. His Trojans spent a record 33 straight weeks at No. 1.

Perhaps it was a sense of unfinished business in the NFL, or maybe it was the looming NCAA sanctions coming for USC, but Carroll returned to the professional ranks in 2010 as head coach of the Seahawks. This time, he also had the title of vice president of football operations. He'd be able to shape the roster.

"In Seattle, he's got a young, talented group of guys," McGinest said. "He's able to build a team the way he wanted to construct a team. I think everything kind of fell together for him."

After two 7-9 seasons, the Seahawks went 11-5 last season and won a playoff game. This year, they won the NFC West title and the top seed in the conference tournament. He is one win from coaching in the Super Bowl, and he'll be able to do it in the city where his head coaching career began.

"I think Seattle is a picture of what Pete wanted to build in New England if he had more time and possibly more control to have the final say on a lot of matters," Bruschi said.

Unlike that veteran-laden Jets team he coached, the 2013 Seahawks do not have any players with 10 or more years of NFL experience. Only seven players have been in the league for more than seven seasons. The second-oldest coach in the league, now 62, has surrounded himself with the fourth-youngest team. Yet they all seem to share that exuberance of youth.

"You don't watch the Seahawks play and say 'Those guys are professionals,' '' said Lageman, now a radio broadcaster for the Jaguars. "When you watch the Seahawks play, it looks like that's a team playing football and they love football. They're so into it. The energy is so high."

The Jaguars played the Seahawks earlier this year, so Lageman got to spend some time with Carroll. He asked his old coach if he still dabbles with the harmonica.

"No," Carroll said, "not as much anymore."

That song's been played. Those car rides to Hofstra are over. He's on to a new challenge.